The technical field of the invention is the control of electric motors, and in particular the control of the electric motors of wound rotor synchronous type.
An electric motor of wound rotor synchronous type comprises a fixed part called stator and a moving part called rotor. The stator comprises three windings offset by 120° and powered by alternating current. The rotor comprises one winding powered by direct current.
The currents of the phases of the stator depend on the resistances and inductances of the rotor and of the stator as well as on the mutual inductance between the rotor and the stator.
The control of such a system requires account to be taken of the control saturation phenomena, due in particular to the voltage limits of the battery.
The document U.S. Pat. No. 3,851,234 discloses a method for avoiding the magnetic saturation by reducing the speed of the motor or the torque supplied.
The document U.S. Pat. No. 5,015,937 discloses the control of a synchronous machine with wound rotor in open loop mode with data tables for avoiding saturations.
Finally, the document U.S. Pat. No. 6,181,091 discloses the control of a synchronous machine with permanent magnet in which the saturation is avoided by modifying the operation of the PWM (Pulse Width Modulation) ensuring the voltages on each branch of the motor.
However, there is no provision in the prior art of a saturation making it possible to maintain a dynamic decoupling of the controls.